Field of the Invention
The present invention relates to detection circuits and detecting methods thereof, and more particularly, to a detection circuit and a detecting method thereof for detecting the state of connection between a signal port and an external device.
Description of the Prior Art
Due to technological development, mobile electronic devices, such as cellular phones and tablets, are increasingly common. Users contact each other and watch movies at any time and any place with the mobile electronic devices. To meet the need for portability, the mobile electronic devices are each equipped with a built-in antenna for receiving wirelessly transmitted signals.
However, the built-in antenna has a small reception area, is rather ineffective in receiving wirelessly transmitted signals, and is susceptible to the deterioration of quality in transmitting signals and playing videos especially in a reception environment rife with weak signals. In view of this, some manufacturers begin expanding docks applicable to mobile electronic devices by disposing antenna slots in the docks so that wirelessly transmitted signals are received by external antennas connected to the docks when the mobile electronic devices are insertedly disposed on the dock, thereby enhancing the transmission quality of the mobile electronic devices.
Nonetheless, in the event of poor electrical connection between a mobile electronic device and a dock or between an external antenna and a dock because of a loose connection, a damaged antenna, a damaged port, or a misaligned port, for example, the signal transmission quality of the mobile electronic device will be unsatisfactory but remain unexplained.